As previously stated, the effective close range focus for the S-series including the S50 in macro mode is 3.9 inches compared to 2 inches with the A70. The A70 can get even closer with the macro lenses too. The S-series including the S40 and S50 have no lens attachments to do the same as the A70.

You never did say what your intentions were for the photographs? If your an amateur then the A70 will be more than enough resolution at 3.2 megapixels and will produce beautiful 8X10 shots. If you want to spend the ~$500 or so for 5 megapixel S50 then I won't stop you. It will do a great job resolution-wise. But if you do purxhase the S50 your lense choice and macro ability will be wiped out.

It's tough decision but seriously though if you have $500 to spare surely you can afford a G3 or equivalent that will meet ALL your needs. As a professional photographer I can attest to purchasing the right camera that does everything you need it too.

As mentioned before the A70 takes macro shots at 2 inches or 5 cm. When you add an adaptor and macro lens this reduces to 3 cm, or a little over 1 inch. Considering that the A70 is good for 8x10 images if they are well focused and free of camera shake (i have printed at this size and still got amazing detail), I'd go for the A70 again. I don't think there are add-on lenses available for the S-series cams, and in any case, unless you want to print at A3-size then you don't need the 5 megapixels. For anything up to 8x10 inch images - your eyes wont be able to tell the difference.